"More than any other biography comic book we have released, this one seems to be only gaining momentum since we announced it," Bluewater Productions publisher Darren G. Davis tells PEOPLE.

"I had to walk a 70-year-old woman through how to order it on Amazon," he adds. "We are getting calls from so many different types of people ... everyone is so excited about this book."

The 40-plus page collector's edition will hit shelves March 30 and retails for $7.99. A follow-up graphic novel, due in May, will include pinup posters, illustrations of the April 29 wedding and a comparison to Prince Charles and Diana's big day.